Hatchetfish : Complete Care Guide

Have you heard of the incredible hatchetfish? This tiny freshwater fish is a top-dweller in aquariums, known for its unique appearance and cool behavior. But, did you know that hatchetfish are also capable of making long, gliding flights using their powerful pectoral fins? That’s right, these little fish can fly!

If you’re a fish hobbyist, you’ll love the hatchetfish. These fish belong to the family Gasteropelecidae and are found in Central and South America. Though you won’t be able to see the hatchetfish’s impressive hunting skills in your home aquarium, you can still enjoy their unique and attractive features. Just make sure to have a tight-fitting lid on your tank, as hatchetfish are known to jump out of the water.

There are several species of hatchetfish available in the pet trade, but only a few are commonly kept by hobbyists. These include the silver hatchet, the black-winged hatchet, the common hatchet, and the marbled hatchet. Each species is unique and offers something different, so you’ll want to consider slight modifications to your tank, decor, or community of fish before adding hatchetfish to your collection.

Appearance

The Hatchetfish gets its name from its unique hatchet-like shape. Their deep bodies and large fins give them the appearance of flying saucers, gliding over the water with grace and beauty. The species is known for its striking appearance, with a silver sheen and contrasting dark green back, dotted with black spots. The sides of the fish are covered with a pattern of pink to brown spots, which change to a light blue color. The fins are light green and transparent, and the caudal fin is a beautiful green color.

Lifespan

The Hatchetfish has a lifespan of around 5 years, but with proper care, they can live longer. These beautiful creatures are a long-term commitment, and with their playful personalities, they will bring joy and excitement to your aquarium for years to come.

Average Size and Growth Rate

The average size of a Hatchetfish is 1 to 1.4 inches (2.5 to 3.5 cm). These little wonders grow at a slow rate and will remain small for their entire lives.

Tank Size

A 10 gallon (37.9 liter) aquarium or larger is fine for hatchetfish, but it must have a tight-fitting lid to prevent them from jumping out. 20 gallons or larger is preferable, however.

Water Parameters

Hatchetfish prefer water with a pH of 6.0 to 7.5 and a hardness of 2 to 15 dGH. The ideal temperature range for these fish is 72°F to 82°F (22°C to 28°C).

Diet

In the wild, Hatchetfish are insect eaters and larva eaters, taking terrestrial and aquatic invertebrates and other zooplankton near the water surface. In the aquarium, they will accept dried foods of a suitable size but should also be offered regular meals of small live and frozen fare such as Artemia nauplii, Daphnia, Moina, or grindal worms.

One of the biggest challenges with hatchetfish is underfeeding, as they prefer to eat from the surface of the water, so it’s best to feed them floating foods, such as high-quality flakes, floating pellets, freeze-dried foods, or live baby brine shrimp. Decrease the water flow near the surface to prevent the food from sinking too quickly.

Housing Requirements

Hatchetfish are inhabitants of exclusively blackwater environments and prefer fallen branches, live plants, and rock outcroppings in their aquarium. A large aquarium with subdued or dimmed LED lighting is recommended, along with plant species that grow up to the surface of the water to simulate their natural environment. Use a dark substrate to simulate the river bottom. To prevent escape, the top of the tank must be completely sealed or the water level lowered.

Behavior and Temperament

Hatchetfish are shoaling fish and should be kept in groups of at least 6, but preferably 10 or more. They are peaceful towards other fishes but may bicker among themselves. They spend most of their time in the top level of the water searching for food.

Types of Hatchetfish

Pygmy Hatchetfish

The Pygmy Hatchetfish, also known as Carnegiella myersi, is a freshwater fish that is native to the Peruvian Amazon basin and also found in Bolivia. These fish are commonly found in small, shaded, and shallow woodland streams in the forest. They are peaceful shoaling fish and must be kept in a group of at least six but preferably more. They are best kept with small, peaceful characins, dwarf cichlids, small catfish, loaches, and rasbora as tankmates.

Pygmy Hatchetfish are insectivores and will feed on small insects on the water surface. In captivity, they will usually accept most prepared foods that float such as flake and small dried insects and bloodworms. The maximum size of Pygmy Hatchetfish is 1 inch and they require a minimum tank of 20 inches in length, with a focus on surface area over volume. The water parameters for Pygmy Hatchetfish are soft and acidic with a hardness below 5 dGH and pH up to 6.6, preferably below 6. The ideal temperature range for these fish is 23-26°C (73-79°F).

Pygmy Hatchetfish are the smallest and most delicate of the known hatchetfishes, with a rounded keel that is shallower than all other hatchetfish species. They have large pectoral fins that are attached by powerful muscles that propel the fish from the water, allowing them to glide considerable distances through the air. They require a well-matured aquarium with floating plants, very little water movement, and dim lighting.

Blackwing Hatchetfish

The Blackwing Hatchetfish, also known as Carnegiella marthae, is a beautifully unique species of freshwater fish that is native to the Caño de Quiribana near Caicara in Venezuela and is thought to range throughout the upper Orinoco drainage in Venezuela and the rio Negro drainage in Amazonian Brazil. This stunning species of hatchetfish is known for its deep ventral profile, black patches and stripes covering most of its silver body, and a gold stripe that stretches horizontally from its gill cover to the base of its tail.

The Blackwing Hatchetfish is a very peaceful species that is best kept in a shoal of at least 12 of its own kind. This gregarious species requires a lot of surface area in their tank, with a dark sand or fine gravel substrate that is densely planted and covered with leaf litter to maintain the tannin level. To keep these fish healthy, they need a tightly fitting aquarium cover to prevent them from jumping and a power head to provide some water movement.

Marbled Hatchetfish

The Marbled Hatchetfish, also known by its scientific name Carnegiella strigata, is a graceful and striking species of fish that will add beauty and excitement to any aquarium setup. This species is native to the Amazonian region of South America and is primarily found in blackwater environments, characterized by their dark, stained water, and abundant overhanging vegetation.

The Marbled Hatchetfish is a shoaling species, so it is recommended to keep them in a group of at least six. To recreate their natural habitat, the aquarium should be heavily planted, with a dark substrate and some floating vegetation. Driftwood branches and dried leaf litter can also be added to the setup, which will drive the establishment of microbe colonies and provide a secondary food source for the fry.

The Marbled Hatchetfish is characterized by its distinctive marbled pattern, with black and silver stripes covering its body.

Silver Hatchetfish

The Silver Hatchetfish is a species of fish that is native to the lower Amazon River Basin in the state of Pará, Brazil, including the lower portions of the rios Tocantins and Guamá. The species was named “levis” by Eigenmann, which means “smooth” in Latin, due to the lack of maxillary teeth in the species.

Their tank should have a good portion of floating plants and a bit of current, and the cover should be tightly fitting as the fish is capable of jumping. The Silver Hatchetfish is sometimes a little reluctant to take dried foods, but it will usually learn to accept them over time with a diet that consists mainly of frozen and live foods like bloodworm and Daphnia. A minimum of half a dozen Silver Hatchetfish should be kept together for them to settle and feel secure.

Spotted Hatchetfish

The Spotted Hatchetfish (Gasteropelecus maculatus) is a unique and fascinating fish species that is highly sought after by aquarists. It is native to the Pacific slopes of Panama, as well as the Pacific and Atlantic drainages of Colombia and the Maracaibo basin of Venezuela.

Spotted Hatchetfish are known for their keeled body shape, large pectoral fins, and silver color with olive brown back and black spots. They are a shy and peaceful species that spend most of their time close to or just under the water surface, where they feed on insects, mosquito larvae, worms, and small crustaceans. Like all hatchetfish, they are known for their ability to leap from the water and glide to catch insects near the surface.

Breeding

Ready to breed hatchetfish? Great! It might sound difficult, but with the right information and a little patience, you’ll be able to successfully breed these unique fish.

To start, you’ll need to know how to differentiate the males from the females. Females are very slightly larger and more rounded than males. However, it can be difficult to differentiate them based on physical characteristics alone. Keep in mind that in a school of common hatchetfish, there are usually more females than males.

Next, create an environment that mimics their natural habitat. You’ll want to put your common hatchetfish in a school of 4 to 6 in a separate aquarium of about 25 gallons (100 L). To imitate their natural water conditions, you can ask the seller where the fish is from and set the temperature accordingly, usually between 22 to 27 °C. Maintain a water hardness of 18 to 216 ppm, a pH of 6 to 7, and a substrate of peat mixed with gravel. Adding floating vegetation and dim lighting will also help reduce stress.

To trigger breeding, you’ll need to provide a rich diet. Live mosquito larvae and fruit flies are great options, as well as bloodworms and small crustaceans like brine shrimp. Let your hatchetfish get used to these new foods for a few weeks, and you’ll know they’re ready to breed when they start a long courtship ritual.

Once the eggs are laid, separate the parents from the main aquarium to prevent them from eating the eggs. The eggs will hatch in 30 to 36 hours and the fry will need to be fed small portions of rotifers, paramecium, and infusoria. As they grow, you can feed them baby brine shrimp and cyclops.

Tankmates

Diseases & Illness

Taxonomy

Tim Priest

Tim Priest, a renowned aquarium expert with over 15 years of experience in aquatic gardening and fish education, is dedicated to helping enthusiasts create stunning and thriving aquatic environments. As the founder of LearnTheAquarium.com, Tim shares his wealth of knowledge, passion, and expertise through engaging articles, educational resources, and personalized advice.

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